Spherical surface drive block for washing machine basket

Abstract

A wash basket alignment system for an automatic washing machine having a wash basket with a drive block partially inserted through a central aperture in the bottom wall of the wash plate. A spin drive tube extends longitudinally through the central aperture in the drive block and through the wash plate bottom wall. A hold down nut is threadingly engaged to the drive block from the inside chamber of the wash basket to position the wash basket within the wash tub. Concentric alignment of the wash basket along a central longitudinal axis decreases basket runout. Therefore, the drive block has a spherical outside surface where it abuts the conical shaped outer surface of the wash basket. The radius of the spherical outside surface intersects the central axis at a point. This configuration facilitates the sliding or moving of this juncture from a first position out of concentricity to a second position that is concentric about the longitudinal axis. Additionally, the hold down nut has a conical shaped underside surface where it abuts the spherical shaped inner surface of the wash basket. A normal taken at this abutment passes through the same point on the central axis. This configuration facilitates movement from a first position out of concentricity to a second position with the wash basket concentric about the longitudinal axis. These two junctures are maintained by tightening the hold down nut.

We claim:  
     
       1. A wash basket alignment system for an automatic washing machine having a wash basket with a bottom wall, said bottom wall having an outer surface and an inner surface, and a spin drive tube extending longitudinally along a generally central axis and through a central aperture in said bottom wall, the system comprising: 
       a rim defining the bottom wall central aperture,  
       a wash basket center portion extending outward from the rim and being generally spherical in shape along the bottom wall inner surface,  
       a wash basket mating portion extending outward from the center portion and being generally conical in shape along the bottom wall outer surface, and  
       a drive block having an upper portion with a central aperture for receiving the spin drive tube, a middle portion having a generally spherical shaped outside surface, and a threaded portion positioned between the upper portion and the middle portion.  
     
     
       2. The wash basket alignment system according to  claim 1 , wherein, 
       the drive block middle portion outside surface and the wash basket mating portion outer surface abut at a mating juncture when the drive block upper portion and threaded portion are inserted through the wash basket central aperture.  
     
     
       3. The wash basket alignment system according to  claim 2 , wherein, 
       the mating juncture is generally circular shaped.  
     
     
       4. The wash basket alignment system according to  claim 2 , wherein, 
       the mating juncture is generally elliptical shaped.  
     
     
       5. The wash basket alignment system according to  claim 2 , wherein, 
       the mating juncture is shiftable from a first position with the wash basket not concentric about the central axis to a second position with the wash basket generally concentric about the central axis, and  
       a hold down nut is threadingly engageable with the drive block threaded portion to maintain the second position.  
     
     
       6. The wash basket alignment system according to  claim 1 , further comprising, 
       a hold down nut having threads and a generally conical shaped underside surface, said threads mating with the drive block threaded portion.  
     
     
       7. The wash basket alignment system according to  claim 6 , wherein, 
       the hold down nut underside surface and the wash basket center portion inner surface about at a second juncture when the hold down nut threads are threadingly engaged with the drive block threaded portion.  
     
     
       8. The wash basket alignment system according to  claim 7 , wherein, 
       the second juncture is generally circular shaped.  
     
     
       9. The wash basket alignment system according to  claim 7 , wherein, 
       the second juncture is generally elliptical shaped.  
     
     
       10. The wash basket alignment system according to  claim 1 , further comprising, 
       a hold down nut having threads and a generally conical shaped underside surface, said hold down nut positioning the wash basket rim and center portion between the hold down nut and drive block middle portion when the hold down nut is threadingly engaged with the drive block threaded portion.  
     
     
       11. The wash basket alignment system according to  claim 10 , wherein, 
       said hold down nut positions the mating portion outer surface adjacent the drive block middle portion outside surface when the hold down nut is threadingly engaged with the drive block threaded portion to form a mating juncture.  
     
     
       12. The wash basket alignment system according to  claim 11 , wherein, 
       the mating juncture moves from a first position when the wash basket is not concentrically aligned about the central axis to a second position when the wash basket is generally concentrically aligned about the central axis.  
     
     
       13. The wash basket alignment system according to  claim 12 , further comprising, 
       a second juncture at which the wash basket center portion abuts the hold down nut conical shaped underside surface when the hold down nut threads threadingly engage the drive block threaded portion.  
     
     
       14. The wash basket alignment system according to  claim 13 , wherein, 
       the second juncture is shifted from a first position when the mating juncture is in the first position to a second position when the mating juncture is in the second position, and  
       the second position is maintained by tightening the hold-down nut to the drive block threaded portion.  
     
     
       15. A wash basket alignment system for an automatic washing machine having a wash basket with a bottom wall, said bottom wall having an outer surface and an inner surface, a drive block with a middle portion, said middle portion having a generally spherical outside surface, and a generally central axis extending though a central aperture in said bottom wall and in said drive block, the system comprising: 
       a point on the central axis defining a radius of the drive block middle portion,  
       a wash basket rim defining the wash basket central aperture,  
       a wash basket center portion extending outward from the rim, said center portion having a generally spherical shaped inner surface, and  
       a point on the central axis defining a radius of the center portion.  
     
     
       16. The wash basket alignment system according to  claim 15 , wherein: 
       the center portion point is the drive block point.  
     
     
       17. The wash basket alignment system according to  claim 16 , further comprising: 
       a wash basket mating portion extending outward from the center portion and being conical in shape along the bottom wall outer surface, and  
       a mating juncture formed by the drive block middle portion and the mating portion such that a normal of the mating portion taken at the mating juncture passes through the drive block point.  
     
     
       18. The wash basket alignment system according to  claim 17 , further comprising: 
       a hold down nut having a generally conical underside surface, and  
       a juncture formed by the center portion inner surface and the hold down nut underside surface such that a normal of the hold down nut underside surface taken at the juncture passes through the drive block point.  
     
     
       19. The wash basket alignment system according to  claim 17 , further comprising: 
       a hold down nut having a generally convex underside surface, and  
       a juncture formed by the center portion inner surface and the hold down nut underside surface.  
     
     
       20. The wash basket alignment system according to  claim 16 , further comprising: 
       a wash basket mating portion extending outward from the center portion and being spherical in shape along the bottom wall outer surface, and  
       a mating juncture formed by the mating portion and the drive bock middle portion such that the mating juncture is generally at a distance from the drive block point equal to the drive block radius.  
     
     
       21. The wash basket alignment system according to  claim 20 , further comprising: 
       a hold down nut having a generally conical underside surface, and  
       a juncture formed by the center portion inner surface and the hold down nut underside surface such that a normal of the hold down nut underside surface taken at the juncture passes through the drive block point.  
     
     
       22. The wash basket alignment system according to  claim 20 , further comprising: 
       a hold down nut having a generally convex underside surface, and  
       a juncture formed by the center portion inner surface and the hold down nut underside surface.  
     
     
       23. A wash basket alignment system for an automatic washing machine having a wash basket with a bottom wall, said bottom wall having an outer surface and an inner surface, a drive block with a middle portion, said middle portion having a generally spherical outside surface, and a generally central axis extending though a central aperture in said bottom wall and in said drive block, the system comprising: 
       a point on the central axis defining a radius of the drive block middle portion,  
       a wash basket rim defining the wash basket central aperture,  
       a wash basket center portion extending outward from the rim, said center portion having a generally conical shaped inner surface.  
     
     
       24. The wash basket alignment system according to  claim 23 , further comprising: 
       a wash basket mating portion extending outward from the center portion and being conical in shape along the bottom wall outer surface, and  
       a mating juncture formed by the drive block middle portion and the mating portion such that a normal of the mating portion taken at the mating juncture passes through the drive block point.  
     
     
       25. The wash basket alignment system according to  claim 24 , further comprising: 
       a hold down nut having a generally convex underside surface, and  
       a juncture formed by the center portion inner surface and the hold down nut underside surface such that a normal of the center portion taken at the juncture passes through the drive block point.  
     
     
       26. The wash basket alignment system according to  claim 23 , further comprising: 
       a wash basket mating portion extending outward from the center portion and being spherical in shape along the bottom wall outer surface, and  
       a mating juncture formed by the mating portion and the drive bock middle portion such that the mating juncture is generally at a distance from the point equal to the drive block radius.  
     
     
       27. The wash basket alignment system according to  claim 26 , further comprising: 
       a hold down nut having a generally convex underside surface, and  
       a juncture formed by the center portion inner surface and the hold down nut underside surface such that a normal of the center portion taken at the juncture passes through the drive block point.